arXiv subjects

Andrea Giammanco

Publications and source records attributed to Andrea Giammanco.

42 records · Page 3Linked to original sources

arXiv2018

Single top-quark production at the Tevatron and the LHC

This paper provides a review of the experimental studies of processes with a single top quark at the Tevatron proton-antiproton collider and the LHC proton-proton collider. Single top-quark production in the t-channel process has been measured at both colliders. The s-channel process has been observed at the Tevatron, and its rate has been also measured at the center-of-mass energy of 8 TeV at the LHC in spite of the comparatively harsher background contamination. LHC data also brought the observation of the associated production of a single top quark with a W boson as well as with a Z boson. The Cabibbo-Kobayashi-Maskawa matrix element |Vtb| is extracted from the single-top-quark production cross sections, and t-channel events are used to measure several properties of the top quark and set constraints on models of physics beyond the Standard Model. Rare final states with a single top quark are searched for, as enhancements in their production rates, if observed, would be clear signs of new physics.

hep-ex↗

arXiv2017

TOP2017: Experimental Summary

At the time of the 10th International Workshop on Top Quark Physics (TOP2017), top quark physics is a very dynamic research area. Thanks to the unprecedentedly fast accumulation of high-energy data at the LHC during the ongoing Run~2, statistical starvation is a matter of the past for most of the traditional top-quark analyses, that are now experiencing the luxury of having to worry about how to punch through the "Systematics Wall" and maximize the utility of their data. New processes involving top quarks are being studied for the first time, and the good old pair-production processes are being explored in unusual settings, such as collisions involving heavy ions, or "reference data" collected by the LHC at relatively low centre-of-mass energy. The TOP2017 conference featured 37 talks delivered by experimental physicists, including seven in the "Young Scientists Forum" where young colleagues were given the opportunity to elaborate more deeply than usual on their own work. As it is impossible to do justice to all the experimental results presented at this conference while staying within a reasonable length, this document contains a very biased selection, mostly based on the personal taste of the author.

hep-ex↗

arXiv2017

Working Group 5: Physics with Heavy Flavours

This paper summarises a few selected topics discussed during Working Group 5 of the Deep Inelastic Scattering 2017 conference, Physics with Heavy Flavours, related to the study of charm, bottom, and top quark physics. While the programme of this Working Group was structured by thematic areas, this conference was the occasion for intense cross-pollination between traditionally disjoint research lines. The four LHC experiments all contribute to heavy-flavour physics, with some degree of overlap in most areas, while experiments at other accelerators provide vital input in complimentary kinematic regions. Theorists now have the possibility to take inputs from more sources, and experimentalists focus on measurements that maximise utility. The interplay of LHC heavy quark cross-section measurements with DIS expertise is greatly improving PDF precision, leading to much improved models that, amongst other things, better inform the prospects for future colliders.

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arXiv2015

Single top quark production at the LHC

This paper is an experimental review of the study of processes with a single top quark at the LHC. The pioneering times are over, and this is now a sector of "precision physics" at colliders. Angular distributions of the decay products of singly-produced top quarks are unique tests of the electroweak interaction. Searches for rare final states of the form t+X (where X=$γ$, Z, H) are very sensitive to new physics, and will enter with Run II in a very interesting zone of the parameter space of some theories. The relative sign of the Yukawa coupling of the top quark with respect to the Higgs coupling to gauge bosons will be conclusively measured very soon in the tHq final state.

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arXiv2015

Heavy baryons as polarimeters at colliders

In new-physics processes that produce b or c jets, a measurement of the initial b or c-quark polarization could provide crucial information about the structure of the new physics. In the heavy-quark limit, the b and c-quark polarizations are preserved in the lightest baryons they hadronize into, Lambda_b and Lambda_c, respectively. We revisit the prediction for the polarization retention after the hadronization process and extend it to the case of transverse polarization. We show how ATLAS and CMS can measure the b-quark polarization using semileptonic Lambda_b decays, and the c-quark polarization using Lambda_c+ -> p K- pi+ decays. For calibrating both measurements we suggest to use ttbar samples in which these polarizations can be measured with precision of order 10% using 100/fb of data in Run 2 of the LHC. Measurements of the transverse polarization in QCD events at ATLAS, CMS and LHCb are motivated as well. The proposed measurements give access to nonperturbative QCD parameters relevant to the dynamics of the hadronization process.

hep-ph↗

arXiv2012

Top quark physics prospects with 10 fb^{-1} at 7 TeV

This paper presents a personal point of view on the prospects open for top quark physics analyses at the LHC with 10 fb$^{-1}$ of pp collisions at 7 TeV. We discuss the main directions for improvement for the analyses presented at TOP2011 when moving to a regime where systematic uncertainties are the limiting factors, and suggest some new studies that become possible for the first time thanks to the larger statistics.

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